The new project is dedicated to Europe’s remaining medieval stone arch bridges. Surprisingly, this important corpus of medieval constructions has received very little attention by building archeology so far, although the complexity and importance of bridge projects was comparable to cathedral building, and bridges attract great interest by the general public. Establishing a permanent stone arch bridge posed a serious financial and technical challenge to medieval communities, tasks ranging from stone quarrying and stoneworking, laying the foundations in the riverbed, to the final easing of the centring under the completed arches.
On-site building archeology is the most promising approach to untangle the bridges’ building and repair history, since archival sources (although abundant) typically provide very little technical detail. In the project, detailed geometrical surveys of the bridges will be created by means of advanced technologies like laser scanning, structure-from-motion photogrammetry employing drone-mounted or cable-car-suspended cameras, as well as automated feature extraction. Precise surveys permit to correlate findings and traces and to reconstruct details of the design and construction procedures. Contextualization of the individual monuments will be achieved by focusing on some particularly dense clusters of preserved bridges, notably, in Southwestern France and Central Italy.
Roof structure of the reformed church in Horgen. (Photo: Jasmin Schäfer, 2018)
Roof structures: The Development of Early Modern timber structures between 1650 and 1850 in the Reformed Church Buildings of German-speaking Switzerland
ETH Zurich, 2021
The reformed churches of Switzerland built between 1650 and 1850 posed new technical challenges to the master builders of the time: the difficulty of spanning even larger rooms without supports to allow an unobstructed view of the pulpit as the liturgical centre required innovative solutions. With remarkable skills, the master builders and architects created impressive timber structures with spans of much more than ten meters, most of which are still in very good condition. Together with the covered timber bridges, they are among the most precious heritage examples of Swiss carpentry.
However, despite the awareness of these extraordinary achievements, there exists only rarely reliable documentation of the constructions. Therefore, within the framework of the project "Evolution of the wide-span timber roof in northern and central Switzerland 1600 - 1850", funded by the Swiss National Science Foundation, the existing roof constructions of reformed churches in German-speaking Switzerland were to be studied comprehensively for the first time. On the basis of selected objects, the existing structures were to be documented and analysed in order to be able to derive a development in the construction history. In addition to traditional methods of hand surveying with a focus on detailed documentation of the joints, technical tools such as the total station and the laser scanner were also used to create deformation-true sets of plans. The drawing of three-dimensional models made it possible to visualise the assembly processes of very complex structures. The research included the examination of archive material as well as the identification of the responsible master builders and carpenters. This allowed an insight into the planning and building processes of timber structures of the time. The research has uncovered numerous craftsmanship innovations that had not previously been paid attention to, like the virtuoso constructions of the Haltiner family from the Rhine Valley.
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Dachkonstruktionen: Die Entwicklung frühneuzeitlicher Holztragwerke zwischen 1650 und 1850 im reformierten Kirchenbau der Deutschschweiz (Diss., 2021)
Schäfer, J.: Dachkonstruktionen: Die Entwicklung frühneuzeitlicher Holztragwerke zwischen 1650 und 1850 im reformierten Kirchenbau der Deutschschweiz. Diss, ETH Zürich, 2021. (Research Collection)
Schäfer, J.: Late 18th-century innovation: The first Mediterranean purlin roof truss in German-speaking Switzerland at Embrach ZH. In: Mascarenhas-Mateus, J. et al. (Eds.): History of Construction Cultures: Proceedings of the 7th International Congress on Construction History, 2021, Lisbon. London: CRC Press, 2021, Vol. I, 225–231. (Research Collection)
Schäfer, J.: Eine weitgespannte Holzbrücke nach dem Vorbild eiserner Konstruktionen: David Vogels Wettbewerbsentwürfe für das Brückenprojekt in Eglisau ZH. In: Materialgerecht konstruiert!?! Schriftenreihe der Gesellschaft für Bautechnikgeschichte, 2021, Bd. 4, im Reviewprozess.
Gantner, M.; Schäfer, J.: «Zimmer-Jost», der Nachlass des Münsterer Baumeisters Jost Kopps als Spiegel ländlichen Baugewerbes in der Zeit um 1800. In: Der Geschichtsfreund. Luzern: Historischer Verein Zentralschweiz, 2021, Bd. 174, 107–124. (Research Collection)
Schäfer, J.; Wasser, R. Langenberg, S.: Für das Image der Denkmalpflege. In: Denkmalpflege – uncool und ungeliebt? NIKE-Bulletin 3/2021, 21–27. (Research Collection)
Schäfer, J.: Die weitgespannte Dachkonstruktion der reformierten Kirche in Horgen – Ein Meisterwerk des 18. Jahrhunderts im Kontext des reformierten Kirchenbaus der Deutschschweiz. In: Herausforderung der Spannweite, Holzbau 1500–1900 in der Schweiz und anderswo. Publikation in Vorbereitung.
Schäfer, J.; Bastgen, M. M.: Das Dachwerk der reformierten Kirche Wädenswil - Grubenmanns makelloses Meisterwerk? In: Stefan M. Holzer et. al. (Eds.): Reparieren – Ertüchtigen – Erhalten: Ansätze und Strategien seit der Antike. Schriftenreihe der Gesellschaft für Bautechnikgeschichte. Petersberg: Michael Imhof Verlag, 2019, Bd. 3, 85–105. (Research Collection)
Schäfer, J.; Holzer, S. M.: Vision und Wirklichkeit: Modelle Schweizer Holzbrücken des 18. Jahrhunderts. In: Kunst + Architektur in der Schweiz 4/2018, 32–39. (Research Collection)
Schäfer, J.; Holzer, S. M.: Beyond Grubenmann: Swiss carpentry (1750–1850). In: Wouters, I., et al. (Eds.): Building Knowledge, Constructing Histories: Proceedings of the 6th International Congress on Construction History, 2018, Brussels, Belgium. London: CRC Press, 2018, Vol. II, 1163–1170. (Research Collection)
Schäfer, J.; Kojder K: Erfurt, Benediktsplatz 1. Bauforschung in den mittelalterlichen Kelleranlagen. In: Schulz-Brize T., et al. (Eds.): Bauforschung und Denkmalpflege 1.2017, Jahrbuch des Fachgebietes Historische Bauforschung und Baudenkmalpflege Technische Universität Berlin, 2017, Berlin: Universitätsverlag TU Berlin, 74–78. (Research Collection / external page DOI Download)
